对焦环

.focus-ring 辅助工具移除了 :focus 上的默认 outline，并将其替换为可更广泛自定义的 box-shadow。新的阴影由一系列 CSS 变量组成，这些变量继承自 :root 级别，可以针对任何元素或组件进行修改。

🌐 The .focus-ring helper removes the default outline on :focus, replacing it with a box-shadow that can be more broadly customized. The new shadow is made up of a series of CSS variables, inherited from the :root level, that can be modified for any element or component.

示例

🌐 Example

直接点击下面的链接查看聚焦环的效果，或进入下面的示例，然后按 Tab。

<a href="#" class="d-inline-flex focus-ring py-1 px-2 text-decoration-none border rounded-2">
  Custom focus ring
</a>

定制

🌐 Customize

使用我们的 CSS 变量、Sass 变量、工具或自定义样式修改聚焦环的样式。

🌐 Modify the styling of a focus ring with our CSS variables, Sass variables, utilities, or custom styles.

CSS 变量

🌐 CSS variables

根据需要修改 --bs-focus-ring-* CSS 变量以更改默认外观。

🌐 Modify the --bs-focus-ring-* CSS variables as needed to change the default appearance.

<a href="#" class="d-inline-flex focus-ring py-1 px-2 text-decoration-none border rounded-2" style="--bs-focus-ring-color: rgba(var(--bs-success-rgb), .25)">
  Green focus ring
</a>

.focus-ring 通过全局 CSS 变量设置样式，这些变量可以在任何父元素上被覆盖，如上所示。这些变量是从它们的 Sass 变量对应项生成的。

--#{$prefix}focus-ring-width: #{$focus-ring-width};
--#{$prefix}focus-ring-opacity: #{$focus-ring-opacity};
--#{$prefix}focus-ring-color: #{$focus-ring-color};

默认情况下，没有 --bs-focus-ring-x、--bs-focus-ring-y 或 --bs-focus-ring-blur，但我们提供带有初始 0 值回退的 CSS 变量。修改它们可以改变默认外观。

🌐 By default, there is no --bs-focus-ring-x, --bs-focus-ring-y, or --bs-focus-ring-blur, but we provide CSS variables with fallbacks to initial 0 values. Modify them to change the default appearance.

<a href="#" class="d-inline-flex focus-ring py-1 px-2 text-decoration-none border rounded-2" style="--bs-focus-ring-x: 10px; --bs-focus-ring-y: 10px; --bs-focus-ring-blur: 4px">
  Blurry offset focus ring
</a>

Sass 变量

🌐 Sass variables

自定义聚焦环 Sass 变量，以修改 Bootstrap 支持的项目中聚焦环样式的所有使用情况。

🌐 Customize the focus ring Sass variables to modify all usage of the focus ring styles across your Bootstrap-powered project.

$focus-ring-width:      .25rem;
$focus-ring-opacity:    .25;
$focus-ring-color:      rgba($primary, $focus-ring-opacity);
$focus-ring-blur:       0;
$focus-ring-box-shadow: 0 0 $focus-ring-blur $focus-ring-width $focus-ring-color;

Sass 工具 API

🌐 Sass utilities API

除了 .focus-ring，我们还有几个 .focus-ring-* 工具可用于修改辅助类的默认值。可以使用我们的任意 主题颜色 来修改颜色。请注意，根据当前的颜色模式支持，浅色和深色变体在所有背景颜色上可能不可见。

🌐 In addition to .focus-ring, we have several .focus-ring-* utilities to modify the helper class defaults. Modify the color with any of our theme colors. Note that the light and dark variants may not be visible on all background colors given current color mode support.

<p><a href="#" class="d-inline-flex focus-ring focus-ring-primary py-1 px-2 text-decoration-none border rounded-2">Primary focus</a></p>
<p><a href="#" class="d-inline-flex focus-ring focus-ring-secondary py-1 px-2 text-decoration-none border rounded-2">Secondary focus</a></p>
<p><a href="#" class="d-inline-flex focus-ring focus-ring-success py-1 px-2 text-decoration-none border rounded-2">Success focus</a></p>
<p><a href="#" class="d-inline-flex focus-ring focus-ring-danger py-1 px-2 text-decoration-none border rounded-2">Danger focus</a></p>
<p><a href="#" class="d-inline-flex focus-ring focus-ring-warning py-1 px-2 text-decoration-none border rounded-2">Warning focus</a></p>
<p><a href="#" class="d-inline-flex focus-ring focus-ring-info py-1 px-2 text-decoration-none border rounded-2">Info focus</a></p>
<p><a href="#" class="d-inline-flex focus-ring focus-ring-light py-1 px-2 text-decoration-none border rounded-2">Light focus</a></p>
<p><a href="#" class="d-inline-flex focus-ring focus-ring-dark py-1 px-2 text-decoration-none border rounded-2">Dark focus</a></p>

对焦环工具在我们的实用程序 API scss/_utilities.scss 中声明。了解如何使用实用程序 API。

🌐 Focus ring utilities are declared in our utilities API in scss/_utilities.scss. Learn how to use the utilities API.

"focus-ring": (
  css-var: true,
  css-variable-name: focus-ring-color,
  class: focus-ring,
  values: map-loop($theme-colors-rgb, rgba-css-var, "$key", "focus-ring")
),